PS D:\learn-dawn> shopify theme serve
X You are not authorized to edit themes on kidszone-theme.myshopify.com.
Make sure you are a user of that store, and allowed to edit themes.
Make sure if this is a development store, you are logged in as a store owner. Since the staff members can not edit the themes on the development stores as per Shopify’s documentation. Please try logging in using the store owner account. Please read this link for more details: https://shopify.dev/themes/tools/cli/getting-started
The steps described in this video solved my issue, thanks, i.e. log out everywhere, log back in, making sure to the correct store (as store owner in my case), and I had access to edit theme.
The error was when I had created the store the first time; I was logging through the application. As this option and I didn’t access it for the first time through this link {shop}.myshopify.com/admin
Apparently, the app did not achieve to complete all the configuration, so I needed to open this link in another browser without cookies logging {shop}.myshopify.com/admin and then, logging there, this application asked me for multiple things about connecting with the new storage. and finally, I made shopify login --store {shop}.myshopify.com on the terminal, and then shopify theme serve